In my opinion, the single biggest addition to C++11 is the Lambda function and expressions (for more features in C++ click here…).

Look at the case when you are calling std::sort function, you have to specify the comparator function and then pass that function as an argument to std::sort. In such situations, you may want to specify the function at the point of calling std::sort inline. Because that function (Comparator Function) has not other use but to be called to this API. This function may not even have a name , we don’t really care..